LED current control circuits and methods
US7683553B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 1, 2007 |
| Grant date | Mar 23, 2010 |
| Priority date | — |
| Expiry date | Jun 6, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Embodiments of the present invention include circuits and methods for electrical current control. In one embodiment, a regulator provides power to the anode end of a set of LED strings. A current setting circuit derives its current from a current reference and generates multiple matching currents that drive the low side (cathode end) of the set of LED strings. The current setting circuit also contains a feedback signal to the regulator that helps maintain a desired voltage level to the anode end of the LED strings. This embodiment is designed to be expandable and drive any number of LED strings. The present invention may be implemented with a high or low side driver scheme to drive the current. Also, the present invention may be implemented with bipolar, nmos, pmos, or any device that operates as a transistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.